Ths invention relates to an intake means for an internal combustion engine and more particularly to an improved induction system, particularly adapted for use with V type engines.
As is well known, the induction system for an internal combustion engine, particularly for automotive application, must be a compromise if conventional induction systems employing only a single intake passage for each cylinder are employed. That is, a conventional induction system must be tuned to give either optimum performance at low speeds or maximum power. With conventional systems, it is impossible to obtain both good low speed running and maximum power output. For that reason, most automotive engines enbodying conventional induction systems represent a compromise in induction system tuning and design.
Recently it has been proposed to employ a so-called dual type of induction system wherein two or more induction passages serve the same chamber of the engine and which incorporates a throttle valve arrangement so that one induction passage serves primarily the low speed and mid-range running conditions while both induction passages are employed to achieve maximum power output. An example of such an induction system is shown in Application for U.S. patent Ser. No. 597,815, filed Apr. 9, 1984, which is a continuation of application Ser. No. 332,825, filed Dec. 21, 1981, entitled "Intake System For Multi-Intake Valve Type Engine and assigned to the same assignee of this application.
Although induction systems of this type can be employed for achieving good running under a wide range of running conditions, they are obviously more complicated than the conventional systems that employ only a single induction passage for each chamber. In addition to the aforenoted advantages, the use of two induction passages for each chamber of the engine permits each induction passage to be tuned so as to be more suitably perform under the respective running condition which it serves. An example of such a tuning arrangement is disclosed in Application for U.S. patent Ser. No. 586,886, filed Mar. 9, 1984, which is a continuation of application Ser. No. 333,940, filed Dec. 23, 1981, entitled "Intake System for Multiple Intake Valve Type Engines and assigned to the same assignee of this application.
Although induction systems of the type described obviously offer considerable advantages over conventional induction systems, they are particularly difficult to adapt to engines having non-aligned cylinders, such as engines of the V or opposed type. With engines of this type, particularly those embodying narrow V angles, it is difficult to position all of the necessary induction conduit within the V of the engine and also to achieve the aforenoted tuning effects.
It is, therefore, a principal object of this invention to provide an improved induction system for an internal combustion engine.
It is a further object of this invention to provide an improved induction system for an engine having non-aligned cylinders.
It is a further object of this invention to provide an improved induction system for an engine of the V type and which employs two intake passages for each cylinder and in which the intake passages are tuned separately from each other.